During the final years of his life, Hiraku Machio remained confined to a hospital bed with a terminal illness until he finally passed away. Taking pity on the unfair life he lived, a god decides to reincarnate Hiraku in another world where he can live as he pleases. Wanting to try farming in this new life, he is bestowed with an all-in-one Almighty Farming Tool that can transform into any useful implement he wishes. Hiraku is then transported to a forest seemingly far from civilization. Here, he plans to build and farm everything from scratch—gradually developing the lifeless area into a thriving new society.

In a thoughtless blunder, God accidentally strikes down Touya Mochizuki with a stray bolt of lightning! As an apology, God offers him one wish and the chance to live again in a magical fantasy world. Touya happily accepts the offer and, for his one wish, asks only to keep his smartphone with him as he begins his journey into this mysterious world. Starting over in this new world, Touya finds it is filled with magic—which he has an affinity for—and cute girls vying for his attention. These girls—the twins Linze and Elze Silhoueska, Yumina Urnea Belfast, Leen, and Yae Kokonoe—provide Touya with no end of romantic frustrations, but also companionship as he discovers the secrets of this new world.

Touya Mochizuki grows accustomed to his new life in another world. Armed with his trusty smartphone, the teenager accepts small quests at his leisure while spending time with his new fiancées: Yumina Urnea Belfast, Yae Kokonoe, and twin sisters Linse and Elze Shileska. But even in a relaxing environment, Touya is only beginning to understand the responsibilities that come with these engagements. In addition to his romantic woes, the elder fairy Lean wishes to locate the remaining pieces of Babylon, the floating island that the mysterious Professor Regina Babylon created five thousand years ago. Touya reluctantly accepts her request and seeks out the teleportation circles that will lead to the islands. However, strange monsters have emerged—possibly powerful enough to destroy the world. In order to save the second life he was given, Touya must weaponize ancient technologies to fight these monsters—all while balancing his overwhelming number of relationships.

The story follows the adventures of rabbit-shaped Jewelpet Ruby, her long-best human friend Airi Kirara and the other Jewelpets on their mission to restore the Jewel Castle, which had fallen from the skies into the middle of the town because of humanity's lack of faith in magic. To restore people's belief in magic, Jewelpets transform into humans to study more about them. (Source: ANN, edited)